Repeated work in loop (ARCH4072)

Key java.performance.repeated-work-in-loop · Severity info · Category performance

A computation whose inputs do not depend on the loop variable produces the same result every iteration. Such work should be hoisted out of the loop to avoid repeating it.

Incorrect

for (Order order : orders) {
    if (order.getTotal() > config.getThreshold() * rate.getFactor()) {
        flag(order);
    }
}

Correct

double limit = config.getThreshold() * rate.getFactor();
for (Order order : orders) {
    if (order.getTotal() > limit) {
        flag(order);
    }
}

Fix

Move computations that do not depend on the loop variable into a variable outside the loop.